In recent years, there have been increasing developments of apparatuses capable of exerting their performance in high-vacuum environments (hereinafter, referred to as vacuum apparatuses), such as vacuum thermal insulation members, vacuum thermal insulation containers, plasma displays.
For these vacuum apparatuses, residual gasses remaining during fabrication thereof and gasses introduced therein with time cause pressure rises inside thereof, which cause degradations of their performance. Therefore, attempts have been made to apply gas-adsorbing members thereto for absorbing such gasses.
If a gas-adsorbing member contacts with air in the atmosphere, the gas-adsorbing member absorbs the air, thereby degrading its gas absorbing ability. Therefore, attempts have been made to cover such a gas-adsorbing member with a low gas-permeable container or low gas-permeable material (refer to PLT 1, for example).
Further, when a gas-adsorbing member is required to be thermally treated for exerting its absorbing property, in order to cover the gas-adsorbing member with a low gas-permeable container for sealing it, it is effective to employ a method which preliminarily installs a set of a low gas-permeable container and a sealing member within a heating oven and, further, raises the temperature therein, for thermally treating the gas-adsorbing member and melting the sealing member through the same processing, thereby attaining sealing.
As a conventional method for attaining such sealing, there has been a method disclosed in PLT 2, for example. Hereinafter, with reference to FIG. 23A and FIG. 23B, there will be described a conventional sealing method. As illustrated in FIG. 23A, internal container 1 and outer container 3 provided with ventilation hole 2 are bonded with end portion 4 to form a double structure, such that ventilation port 2 is an upside, and sealing member 5 is placed therearound. Sealing plate 6 is placed on sealing member 5 and, thereafter, vacuum heating treatment is performed thereon in a vacuum heating oven, so that a vacuum is created in the space formed by inner container 1 and outer container 3 and, thereafter, sealing member 5 is softened. This causes sealing plate 6 to get closer to outer container 3 due to its weight, which creates the state of FIG. 23B, thereby attaining sealing of ventilation hole 2.
However, with the method described in PLT 1, it is impossible to ensure that the low gas-permeable material covering the gas-adsorbing member has a sufficient gas barrier property. Therefore, the gas-adsorbing member absorbs ambient gasses during the processing for installing the gas-adsorbing member in the space containing gas to be absorbed thereby, which has made it hard to suppress degradations of the absorption member.
Further, with the method described in PLT 2, there is a need for use of the three members which are inner container 1, outer container 3 and sealing plate 6, thereby involving larger material costs and a larger number of processes. Therefore, with this method, it has been hard to reduce the costs for the air absorption device.